(1) Field of the Invention
This invention is related to adhesive compositions and more particularly to an adhesive joint formation for doing repair work of a damaged metallic portion of an aircraft or the like under field conditions.
(2) Statement of Prior Art
In the production and utilization of articles formed of metals, minor faults are often generated either in the production process itself or as a result of damage in service. Frequently the faults are of such nature that repair would be possible if an economical and otherwise satisfactory repair process existed. Fabrication of adhesive joints to be used to make repairs in the field do not have the durability or moisture resistance of adhesive joints fabricated under controlled conditions because low temperature (less than 200.degree. F.) and low pressures less than (14 lbs. per sq. in.) conditions are used under humid conditions. Under manufacturing conditions, high temperature, high pressure and dry conditions can be used through the use of expensive and massive autoclave facilities. However, in order to conduct repairs in field it is desirable to prepare surfaces in such a manner that more durable field fabrication can be effected than is presently possible. Furthermore, repair of aircraft or like equipment must be accomplished as much as possible on board the aircraft carrier which has limited space, equipment, and talent relative to the manufacturing facilities. Thus the procedure required must be kept simple and straightforward. It is known that metal oxide-epoxy joints are far more susceptible to moisture degradation than the epoxy-epoxy joints. Under field conditions, it is difficult to properly form the metal oxide on repair patches, to apply corrosion and inhibitor coatings and effect the adhesive joint. It is thus desirable to have an improved method by which metal-oxide-epoxy joints are easier to accomplish under field conditions.